-LRB- CNN -RRB- -- She had come alone to the Richmond High School homecoming dance , gorgeous in a sparkling purple dress and faux diamond baubles . The DJ played salsa , meringue , rap . When the teenager disappeared , her friends thought she had gone home early .

Except she never said goodbye .

`` We were going to go look for her , '' said Kami Baker , 16 , a junior at the school .

The next day , Baker learned the ugly truth about what had happened to her friend .

According to police , she had been gang raped and beaten for almost 2 1/2 hours and left unconscious under a bench shortly before midnight Saturday night .

`` I busted up crying , '' Baker said .

The campus incident in the Bay Area city north of Oakland has shaken students and their families . Baker was one of many people connected to the school and the community who lashed out at officials at a public safety hearing Wednesday .

Baker blamed school district officials for not doing enough to protect her school -- and her friend . She said none of the four officers who were at the homecoming dance was patrolling the school premises even though there were a dozen young men hanging out just a few feet from the gym entrance . She says school officials chose not to take any action .

`` I looked outside of the gym and I saw 12 to 15 guys , sitting there , with no IDs , '' Baker said at the hearing . `` The officers -- not only did they not check the IDs of those students or men sitting outside of of our campus , but the security officers who are employed here did no ... checking either . The assistant principal looked outside and actually saw those men , and did nothing about it . ''

Baker took the podium with her younger sister , Barbie , a freshman at the school , who had spent a chunk of Saturday evening with the rape victim .

`` This story has disrupted the school 's morale greatly , including my own . I am friends with the girl , '' Baker said . `` When I started here , I felt extremely unsafe and so did she , due to the lack of police officers and security officers . ''

Baker later described the 15-year-old girl as a churchgoer who struggled to fit in at Richmond High .

Four teenagers were arraigned Thursday on charges connected to the incident . Cody Ray Smith , described by the court as over 14 years old , pleaded not guilty to charges of rape with a foreign object and rape by force .

Two other juveniles , Ari Abdallah Morales and Marcelles James Peter , appeared together with Smith at the Contra Costa County Superior Court , but did not enter a plea . The court described Morales as under 16 , and did not give an age for Peter .

All three juveniles , who wore bulletproof vests at the hearing , were charged as adults . A fourth individual , Manuel Ortega , 19 , appeared separately without an attorney and did not enter a plea . He did not wear a protective vest . Another adult who was arrested has a different court date .

As many as 10 people were involved in the assault in a dimly lit back alley at the school , police have said . Another 10 people watched , without calling 911 , police said .

The victim was released from a hospital Wednesday , police said .

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NEW : Cody Smith , Ari Morales , Marcelles Peter , Manuel Ortega appear in court

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Kami Baker , a junior at Richmond High , describes night of homecoming dance

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Baker said she was a friend of gang rape victim , says they did n't feel safe at school

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Baker says 15-year-old victim is a churchgoer who struggled to fit in